A keypunch is a device for manually entering data into punched cards by precisely punching holes at locations designated by the keys struck by the operator. Early keypunches were manual devices. Later keypunches were mechanized, often resembled a small desk, with a keyboard similar to a typewriter, and with hoppers for blank cards and stackers for punched cards. Some keypunch models could print at the top of columns, the character punched in each of those columns. The small pieces punched out by a keypunch fell into a chad box, or (at IBM) chip box, or bit bucket.

In many data processing facilities the punched cards were verified by keying exactly the same data a second time and then checking to see if the second keying and the punched data were the same. There was a great demand for keypunch operators, usually women, who worked full-time on keypunch and verifier machines, often in large keypunch departments with dozens or hundreds of other operators.

Keypunches were popular through the 1970s but were rapidly made obsolete by the availability of inexpensive CRT computer terminals